Association between preoperative central sensitization-related symptoms and poor postoperative pain improvement after total knee arthroplasty: an exploratory analysis.

PURPOSE: Higher preoperative Central Sensitization Inventory (CSI) scores may be associated with poor pain improvement after total knee arthroplasty (TKA); sex differences in this association remain unclear. We investigated whether sex modifies the association between preoperative CSI scores and pain improvement after TKA.

METHODS

This multicenter prospective cohort study included patients undergoing primary unilateral TKA. Poor postoperative pain improvement at three months after TKA was defined as failure to achieve the minimal clinically important difference (10 points) on the Knee injury and Osteoarthritis Outcome Score pain subscale. Logistic regression analyses were performed to examine associations between preoperative CSI scores and poor pain improvement, including an interaction term between CSI scores and sex, with adjustment for age, body mass index, pain intensity, pain catastrophizing, anxiety, and depression.

RESULTS

Of 210 enrolled patients (48 males, 162 females; mean age, 73.8 ± 7.8 years), 192 were included. Higher preoperative CSI scores were associated with greater odds of poor postoperative pain improvement (odds ratio, 1.115; 95% confidence interval [CI], 1.060-1.173; P <0.001), whereas sex was not associated with the outcome. In the interaction model, higher CSI scores remained associated with poor pain improvement (OR, 1.142; 95% CI, 1.026-1.271; P = 0.015), whereas neither sex (OR, 1.022; 95% CI, 0.380-2.751; P = 0.966) nor the CSI × sex interaction term (OR, 0.973; 95% CI, 0.873-1.084; P = 0.615) was associated with the outcome.

CONCLUSIONS

Higher preoperative CSI scores were associated with poor postoperative pain improvement after TKA, without a sex interaction.